Invalid Class Typecast

[Andidreas]

Hallo,

ich steh grad ziemlich aufm Schlauch...

Ich hab eine MS SQL Tabelle in der sich zehn Blob Daten Felder befinden --> Typ varbinary(max)
In diese will ich Attachments für einen Mail Versand einfügen...

Zum Testen habe ich mir eine Form gebastelt in der der folgende Source ausgeführt wird:

Delphi-Quellcode:

procedure Tmaintenance_testmailing_form.advglowbtn_sendmailClick(Sender: TObject);

var
i                                                           : Integer;
ms1, ms2, ms3, ms4, ms5, ms6, ms7, ms8, ms9, ms10           : TMemoryStream;
sfn1, sfn2, sfn3, sfn4, sfn5, sfn6, sfn7, sfn8, sfn9, sfn10 : String;

begin

  //Check Entries
  If (StringReplace(edt_mailproject.Text, ' ', '', [rfReplaceAll]) = EmptyStr) Or
     (StringReplace(edt_mailapplication.Text, ' ', '', [rfReplaceAll]) = EmptyStr) Or
     (StringReplace(edt_mailsubject.Text, ' ', '', [rfReplaceAll]) = EmptyStr) Or
     (StringReplace(edt_mailsenderadress.Text, ' ', '', [rfReplaceAll]) = EmptyStr) Or
     (StringReplace(edt_mailsendertext.Text, ' ', '', [rfReplaceAll]) = EmptyStr) Or
     (StringReplace(edt_mailrecipient.Text, ' ', '', [rfReplaceAll]) = EmptyStr) Then
  Begin
    fnDisplayMyActionBox('ERR', 'Error', 'Entries are not complete!', EmptyStr, EmptyStr, EmptyStr, True);
    Exit;
  End;

  //Check count of Attachments
  If lstbox_attachments.Count > 10 Then
  Begin
    fnDisplayMyActionBox('ERR', 'Error', 'More than 10 Attachments!', 'Only max. 10 Attachments allowed!', EmptyStr, EmptyStr, True);
    Exit;
  End;


  Try
    //Load Attachments in Memory Streams
    For i := 0 To lstbox_attachments.Count -1 Do
    Begin
      Try
        Case i of
          //Attachment #1
          0: begin
            ms1 := TMemoryStream.Create;
            ms1.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn1 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #2
          1: begin
            ms2 := TMemoryStream.Create;
            ms2.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn2 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #3
          2: begin
            ms3 := TMemoryStream.Create;
            ms3.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn3 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #4
          3: begin
            ms4 := TMemoryStream.Create;
            ms4.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn4 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #5
          4: begin
            ms5 := TMemoryStream.Create;
            ms5.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn5 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #6
          5: begin
            ms6 := TMemoryStream.Create;
            ms6.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn6 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #7
          6: begin
            ms7 := TMemoryStream.Create;
            ms7.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn7 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #8
          7: begin
            ms8 := TMemoryStream.Create;
            ms8.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn8 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #9
          8: begin
            ms9 := TMemoryStream.Create;
            ms9.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn9 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
          //Attachment #10
          9: begin
            ms10 := TMemoryStream.Create;
            ms10.LoadFromFile(lstbox_Attachments.Items.Strings[i]);
            sfn10 := fnGetFileName(lstbox_Attachments.Items.Strings[i]);
          end;
        End;
      Except
        On E:Exception Do
        Begin
          fnDisplayMyActionBox('ERR', 'Error', 'Could not load Attachment into Memory Stream', lstbox_Attachments.Items.Strings[i], E.Message, EmptyStr, True);
        End;
      End;
    End;

    //Insert Test Record into MS SQL Table Mail
    Try
      With (MSSQL_Query1) Do
      Begin
        Active := False;
        SQL.Clear;
        SQL.Add(' Insert Into "' + ModuleUniDBSchema + '.Mail" ');
        SQL.Add(' ( ');
        SQL.Add(' Mail_Project, Mail_Application, Mail_Subject, Mail_SenderAdress, Mail_SenderText, ');
        SQL.Add(' Mail_Recipient, Mail_CC, Mail_Message, Mail_AttachmentCount, Mail_Stati ');

        For i := 0 To lstbox_Attachments.Count -1 Do
        Begin
          SQL.Add(' , Mail_AttachmentName' + IntToStr(i+1));
          SQL.Add(' , Mail_Attachment' + IntToStr(i+1));
        End;

        SQL.Add(' ) ');

        SQL.Add(' Values( ');
        SQL.Add(' :Mail_Project, :Mail_Application, :Mail_Subject, :Mail_SenderAdress, :Mail_SenderText, ');
        SQL.Add(' :Mail_Recipient, :Mail_CC, :Mail_Message, :Mail_AttachmentCount, :Mail_Stati ');

        For i := 0 To lstbox_Attachments.Count -1 Do
        Begin
          SQL.Add(' , :Mail_AttachmentName' + IntToStr(i+1));
          SQL.Add(' , :Mail_Attachment' + IntToStr(i+1));
        End;

        SQL.Add(' ) ');

        ParamByName('Mail_Project').AsString := edt_mailproject.Text;
        ParamByName('Mail_Application').AsString := edt_mailapplication.Text;
        ParamByName('Mail_Subject').AsString := edt_mailsubject.Text;
        ParamByName('Mail_SenderAdress').AsString := edt_mailsenderadress.Text;
        ParamByName('Mail_SenderText').AsString := edt_mailsendertext.Text;
        ParamByName('Mail_Recipient').AsString := edt_mailrecipient.Text;
        ParamByName('Mail_CC').AsString := edt_mailcc.Text;
        ParamByName('Mail_Message').AsString := mem_mailtext.Text;
        ParamByName('Mail_AttachmentCount').AsString := IntToStr(lstbox_attachments.Count);
        ParamByName('Mail_Stati').AsString := '10';

        For i := 0 To lstbox_Attachments.Count -1 Do
        Begin
          Case i of
            //Attachment #1
            0: begin
              ParamByName('Mail_AttachmentName1').AsString := sfn1;
              ParamByName('Mail_Attachment1').SetBlobData(ms1.Memory, ms1.Size);
            end;
            //Attachment #2
            1: begin
              ParamByName('Mail_AttachmentName2').AsString := sfn2;
              ParamByName('Mail_Attachment2').SetBlobData(ms2.Memory, ms2.Size);
            end;
            //Attachment #3
            2: begin
              ParamByName('Mail_AttachmentName3').AsString := sfn3;
              ParamByName('Mail_Attachment3').SetBlobData(ms3.Memory, ms3.Size);
            end;
            //Attachment #4
            3: begin
              ParamByName('Mail_AttachmentName4').AsString := sfn4;
              ParamByName('Mail_Attachment4').SetBlobData(ms4.Memory, ms4.Size);
            end;
            //Attachment #5
            4: begin
              ParamByName('Mail_AttachmentName5').AsString := sfn5;
              ParamByName('Mail_Attachment5').SetBlobData(ms5.Memory, ms5.Size);
            end;
            //Attachment #6
            5: begin
              ParamByName('Mail_AttachmentName6').AsString := sfn6;
              ParamByName('Mail_Attachment6').SetBlobData(ms6.Memory, ms6.Size);
            end;
            //Attachment #7
            6: begin
              ParamByName('Mail_AttachmentName7').AsString := sfn7;
              ParamByName('Mail_Attachment7').SetBlobData(ms7.Memory, ms7.Size);
            end;
            //Attachment #8
            7: begin
              ParamByName('Mail_AttachmentName8').AsString := sfn8;
              ParamByName('Mail_Attachment8').SetBlobData(ms8.Memory, ms8.Size);
            end;
            //Attachment #9
            8: begin
              ParamByName('Mail_AttachmentName9').AsString := sfn9;
              ParamByName('Mail_Attachment9').SetBlobData(ms9.Memory, ms9.Size);
            end;
            //Attachment #10
            9: begin
              ParamByName('Mail_AttachmentName10').AsString := sfn10;
              ParamByName('Mail_Attachment10').SetBlobData(ms10.Memory, ms10.Size);
            end;
          End;
        End;

        ExecSQL;
      End;
    Except
      On E:Exception Do
      Begin
        fnDisplayMyActionBox('ERR', 'MS SQL Error', 'Could not insert Record into Mail Table!', E.Message, EmptyStr, EmptyStr, True);
      End;
    End;
  Finally
    For i := 0 To lstbox_Attachments.Count -1 Do
    Begin
      Case i of
        0: begin
          If (ms1 <> Nil) Then ms1.Free;
          sfn1 := EmptyStr;
        end;
        1: begin
          If (ms2 <> Nil) Then ms2.Free;
          sfn2 := EmptyStr;
        end;
        2: begin
          If (ms3 <> Nil) Then ms3.Free;
          sfn3 := EmptyStr;
        end;
        3: begin
          If (ms4 <> Nil) Then ms4.Free;
          sfn4 := EmptyStr;
        end;
        4: begin
          If (ms5 <> Nil) Then ms5.Free;
          sfn5 := EmptyStr;
        end;
        5: begin
          If (ms6 <> Nil) Then ms6.Free;
          sfn6 := EmptyStr;
        end;
        6: begin
          If (ms7 <> Nil) Then ms7.Free;
          sfn7 := EmptyStr;
        end;
        7: begin
          If (ms8 <> Nil) Then ms8.Free;
          sfn8 := EmptyStr;
        end;
        8: begin
          If (ms9 <> Nil) Then ms9.Free;
          sfn9 := EmptyStr;
        end;
        9: begin
          If (ms10 <> Nil) Then ms10.Free;
          sfn10 := EmptyStr;
        end;
      End;
    End;
  End;

In der ListBox lstbox_attachments befindet sich der Pfad inkl. Dateinamen zu den Attachments...
Der jeweilige MemoryStream ist auch befüllt (im Debug habe ich die Size überprüft, diese ist > 0)...
Überseh ich hier grad nen Fehler oder warum bekomm ich immer die Fehlermeldung Invalid class Typecast